This invention relates generally to ladder safety devices and particularly pertains to devices for use on the upper end of the type of ladder having a pair of parallel side members of stiles with equispaced transverse rungs.
In the prior art, a number of different ladder safety devices have been provided which can be secured to the upper ends of ladder stiles to increase the area of contact between the upper end of the ladder and the building wall or other resting surface and thereby reduce the risk of ladder slippage. Typical of such apparatus is that which is disclosed in U.S. Pat. No. 4,491,192 wherein a safety device is provided for transverse installation across the end of a ladder and comprises a pair of elongated telescopically slidable members. Another such device is disclosed in U.S. Pat. No. 4,580,661 which utilizes a foam block attachable to the ladder in a transverse position inward from the stile ends and which is particularly adapted to conform with and stabilize the ladder against a roof edge gutter. In U.S. Pat. No. 4,469,194, a rung-attached device is disclosed for use at the end of a ladder and includes a sponge-like member adapted to extend outwardly from the ladder and to be oriented at a selected angle relative to the ladder by means of adjustable clamps on the rung.
The aforementioned prior art devices, and many others not herein discussed which have been introduced for ladder stabilization, have proved extremely useful in providing greater safety for the ladder user. Such devices often, however, are intended for a specific use and lack universality, are quite often costly and cumbersome, and may ignore such factors as protection of the surface against which the ladder is rested or the concept of spreading the area of contact laterally whereby stabilization of the ladder is greatly improved, particularly as compared to that obtainable when only the ladder stile ends contact the resting surface.